Why is my dog's face swollen?

Two days ago, Tuesday, I noticed my dog's neck getting a little puffy; but I didn't worry about it b/c he was acting fine. Wednesday morning... No issues. I get home at 4:30pm and his throat and lower jowl are swollen. He wasn't acting aggressive or timid, just sick and bored. We gave him a benedryl at 6pm and another one at 11pm Wednesday night. This morning, Thursday, the swelling went down, some, and he was a little more active (trying to wag his tail, getting to his feet a little faster), but he still looks so pitiful. He's saliva is sticky looking, and his bottom jaw is a little discolored where his upper jaw is covering. We've just moved a month ago, so I don't know if it is something outside; and we have another dog that is fine. My sick dog is a male husky (not neutered) about 3, and my well dog is a male yorkie (also not neutered) same age. I can't get him to eat, and he tries to drink if I put it in my hands. I don't know what happened or what to do. I've made an appointment, but it's a new vet since the old one retired. Like I said, the swelling went down some (so it's still there) and he's acting so pitiful. I know part of it could be the medicine, but when we tried to dose him this morning he was whining so bad. Please help put my mind at ease a little. I don't know what could've happened.